SUMMARY OF THE INVENTION
A sealed shaft according to the present invention includes a shaft having a coaxial annular portion of reduced diameter bounded by two portions of relatively large diameter and a rolling diaphragm having a rolling wall and attachment means to either end of said rolling wall. One of said attachment means includes a clamping flange for the radially outer end of said rolling diaphragm and the other of said attachment means for the radially inner end of said rolling diaphragm includes a substantially cylindrical member of an elastomeric substance, e.g. natural or synthetic rubber, arranged in coaxial relation to said shaft and surrounding said shaft and having an annular projection conforming substantially to the shape of said portion or reduced diameter of said shaft engaging said portion of reduced diameter of said shaft and exerting a radially inward pressure on said portion of reduced diameter or cavity of said shaft.
The rolling diaphragm includes an elastomeric ply and a fabric reinforcement thereof. The fabric reinforcement is removed, or trimmed off, from the region of the projection of the rolling diaphragm entering into the portion of reduced diameter, or into the cavity, of said shaft. The lack of a fabric reinforcement at this particular point allows a larger radially inward pressure of the projection of the rolling diaphragm than would be possible if the fabric reinforcement were not trimmed off at this particular point.